This class represents
a two-dimensional point pattern dataset. It specifies
- the locations of the points
- the window in which the pattern was observed
- optionally, a ``mark'' attached to each point
(extra information such as a type label).
X is an object of type
it contains the following elements:
x vector of $x$ coordinates of data points
y vector of $y$ coordinates of data points
n number of points
window window of observation
(an object of class
marks optional vector of marks
Users are strongly advised not to manipulate these entries
Objects of class
may be created by the function
and converted from other types of data by the function
Note that you must always specify the window of observation;
there is intentionally no default action of ``guessing'' the window
dimensions from the data points alone.
Standard point pattern datasets provided with the package
data(xxx) to access the dataset
Point patterns may be scanned from your own data files by
scanpp or by using
They may be manipulated by the functions
Point pattern objects can be plotted just by typing
which invokes the
plot method for point pattern objects,
plot.ppp for further information.
There are also methods for
for point patterns. Use
summary(X) to see a useful description
of the data.
Patterns may be generated at random by
Most functions which are intended to operate on a window
will, if presented with a
ppp object instead,
automatically extract the window information from the point pattern.